Recently, with the increased awareness of air pollution and global warming, the development of electric vehicles has gained considerable interest, thus leading to a need for improvements in the performance of secondary batteries. Of specific interest are batteries, which can be minaturized, have a high energy density and which demonstrate a long cycle life.
Non-aqueous electrolyte batteries containing anodes composed of alkali metals such as lithium are an example of known batteries that meet these criteria. Lithium batteries have recently undergone remarkable developments in terms of performance improvement and miniaturization. These developments have required improvements with respect to the material and shape of the anodes and cathodes, and also with respect to the intervening electrolyte.
For example, the thin film design of a Li/composite polymer electrolyte/pyrite (FeS.sub.2) battery offers low manufacture cost, high power and improved safety, as a result of the use of non-aqueous or polymer electrolytes. The Applicant' U.S. Pat. No. 5,472,808 describes a composite solid electrolyte (CSE) for use in rechargeable electrochemical cells such as lithium batteries and also relates to cells that contain such solid electrolytes. These cells, however, suffer from two main drawbacks: slow charge rate and short cycle life.
The lithiated forms of the transition metal chalcogenides, such as: TiS.sub.2, MoS.sub.2, MnO.sub.2, NiO.sub.2, MoO.sub.3, V.sub.2 O.sub.5, V.sub.8 O.sub.13 are commonly used as ca active materials in high energy density lithium, rechargeable batteries.
However the cycle life and safety of these batteries, are insufficient.
One of the main reasons for the decreased reversibility of these lithium batteries is non-compatibility of the cathode active material with the non-aqueous or polymer electrolytes. This non-compatibility is more pronounced in fully charged or fully discharged batteries. The final product of fully reduced cathode material is atomic metal, usually in the form of small aggregates having a large surface area, which are excessively reactive and, therefore, highly susceptible to attack by the electrolyte components causing the electrolyte decomposition and the formation of undesirable products.